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Paul Mundtac44e662009-10-28 17:57:54 +09001/*
2 * Performance event support framework for SuperH hardware counters.
3 *
4 * Copyright (C) 2009 Paul Mundt
5 *
6 * Heavily based on the x86 and PowerPC implementations.
7 *
8 * x86:
9 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
10 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
11 * Copyright (C) 2009 Jaswinder Singh Rajput
12 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
13 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
14 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
15 *
16 * ppc:
17 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
18 *
19 * This file is subject to the terms and conditions of the GNU General Public
20 * License. See the file "COPYING" in the main directory of this archive
21 * for more details.
22 */
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/io.h>
26#include <linux/irq.h>
27#include <linux/perf_event.h>
Paul Gortmakerf7be3452011-07-31 19:20:02 -040028#include <linux/export.h>
Paul Mundtac44e662009-10-28 17:57:54 +090029#include <asm/processor.h>
30
31struct cpu_hw_events {
32 struct perf_event *events[MAX_HWEVENTS];
33 unsigned long used_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
34 unsigned long active_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
35};
36
37DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
38
39static struct sh_pmu *sh_pmu __read_mostly;
40
41/* Number of perf_events counting hardware events */
42static atomic_t num_events;
43/* Used to avoid races in calling reserve/release_pmc_hardware */
44static DEFINE_MUTEX(pmc_reserve_mutex);
45
46/*
47 * Stub these out for now, do something more profound later.
48 */
49int reserve_pmc_hardware(void)
50{
51 return 0;
52}
53
54void release_pmc_hardware(void)
55{
56}
57
58static inline int sh_pmu_initialized(void)
59{
60 return !!sh_pmu;
61}
62
Matt Fleming84c79912010-10-03 21:41:13 +010063const char *perf_pmu_name(void)
64{
65 if (!sh_pmu)
66 return NULL;
67
68 return sh_pmu->name;
69}
70EXPORT_SYMBOL_GPL(perf_pmu_name);
71
Matt Fleming3bf101b2010-09-27 20:22:24 +010072int perf_num_counters(void)
73{
74 if (!sh_pmu)
75 return 0;
76
77 return sh_pmu->num_events;
78}
79EXPORT_SYMBOL_GPL(perf_num_counters);
80
Paul Mundtac44e662009-10-28 17:57:54 +090081/*
82 * Release the PMU if this is the last perf_event.
83 */
84static void hw_perf_event_destroy(struct perf_event *event)
85{
86 if (!atomic_add_unless(&num_events, -1, 1)) {
87 mutex_lock(&pmc_reserve_mutex);
88 if (atomic_dec_return(&num_events) == 0)
89 release_pmc_hardware();
90 mutex_unlock(&pmc_reserve_mutex);
91 }
92}
93
94static int hw_perf_cache_event(int config, int *evp)
95{
96 unsigned long type, op, result;
97 int ev;
98
99 if (!sh_pmu->cache_events)
100 return -EINVAL;
101
102 /* unpack config */
103 type = config & 0xff;
104 op = (config >> 8) & 0xff;
105 result = (config >> 16) & 0xff;
106
107 if (type >= PERF_COUNT_HW_CACHE_MAX ||
108 op >= PERF_COUNT_HW_CACHE_OP_MAX ||
109 result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
110 return -EINVAL;
111
112 ev = (*sh_pmu->cache_events)[type][op][result];
113 if (ev == 0)
114 return -EOPNOTSUPP;
115 if (ev == -1)
116 return -EINVAL;
117 *evp = ev;
118 return 0;
119}
120
121static int __hw_perf_event_init(struct perf_event *event)
122{
123 struct perf_event_attr *attr = &event->attr;
124 struct hw_perf_event *hwc = &event->hw;
Paul Mundt88200022009-11-05 13:56:50 +0900125 int config = -1;
Paul Mundtac44e662009-10-28 17:57:54 +0900126 int err;
127
128 if (!sh_pmu_initialized())
129 return -ENODEV;
130
131 /*
132 * All of the on-chip counters are "limited", in that they have
133 * no interrupts, and are therefore unable to do sampling without
134 * further work and timer assistance.
135 */
136 if (hwc->sample_period)
137 return -EINVAL;
138
139 /*
140 * See if we need to reserve the counter.
141 *
142 * If no events are currently in use, then we have to take a
143 * mutex to ensure that we don't race with another task doing
144 * reserve_pmc_hardware or release_pmc_hardware.
145 */
146 err = 0;
147 if (!atomic_inc_not_zero(&num_events)) {
148 mutex_lock(&pmc_reserve_mutex);
149 if (atomic_read(&num_events) == 0 &&
150 reserve_pmc_hardware())
151 err = -EBUSY;
152 else
153 atomic_inc(&num_events);
154 mutex_unlock(&pmc_reserve_mutex);
155 }
156
157 if (err)
158 return err;
159
160 event->destroy = hw_perf_event_destroy;
161
162 switch (attr->type) {
163 case PERF_TYPE_RAW:
164 config = attr->config & sh_pmu->raw_event_mask;
165 break;
166 case PERF_TYPE_HW_CACHE:
167 err = hw_perf_cache_event(attr->config, &config);
168 if (err)
169 return err;
170 break;
171 case PERF_TYPE_HARDWARE:
172 if (attr->config >= sh_pmu->max_events)
173 return -EINVAL;
174
175 config = sh_pmu->event_map(attr->config);
176 break;
Paul Mundtac44e662009-10-28 17:57:54 +0900177 }
178
179 if (config == -1)
180 return -EINVAL;
181
182 hwc->config |= config;
183
184 return 0;
185}
186
187static void sh_perf_event_update(struct perf_event *event,
188 struct hw_perf_event *hwc, int idx)
189{
190 u64 prev_raw_count, new_raw_count;
191 s64 delta;
192 int shift = 0;
193
194 /*
195 * Depending on the counter configuration, they may or may not
196 * be chained, in which case the previous counter value can be
197 * updated underneath us if the lower-half overflows.
198 *
199 * Our tactic to handle this is to first atomically read and
200 * exchange a new raw count - then add that new-prev delta
201 * count to the generic counter atomically.
202 *
203 * As there is no interrupt associated with the overflow events,
204 * this is the simplest approach for maintaining consistency.
205 */
206again:
Peter Zijlstrae7850592010-05-21 14:43:08 +0200207 prev_raw_count = local64_read(&hwc->prev_count);
Paul Mundtac44e662009-10-28 17:57:54 +0900208 new_raw_count = sh_pmu->read(idx);
209
Peter Zijlstrae7850592010-05-21 14:43:08 +0200210 if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
Paul Mundtac44e662009-10-28 17:57:54 +0900211 new_raw_count) != prev_raw_count)
212 goto again;
213
214 /*
215 * Now we have the new raw value and have updated the prev
216 * timestamp already. We can now calculate the elapsed delta
217 * (counter-)time and add that to the generic counter.
218 *
219 * Careful, not all hw sign-extends above the physical width
220 * of the count.
221 */
222 delta = (new_raw_count << shift) - (prev_raw_count << shift);
223 delta >>= shift;
224
Peter Zijlstrae7850592010-05-21 14:43:08 +0200225 local64_add(delta, &event->count);
Paul Mundtac44e662009-10-28 17:57:54 +0900226}
227
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200228static void sh_pmu_stop(struct perf_event *event, int flags)
Paul Mundtac44e662009-10-28 17:57:54 +0900229{
230 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
231 struct hw_perf_event *hwc = &event->hw;
232 int idx = hwc->idx;
233
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200234 if (!(event->hw.state & PERF_HES_STOPPED)) {
235 sh_pmu->disable(hwc, idx);
236 cpuc->events[idx] = NULL;
237 event->hw.state |= PERF_HES_STOPPED;
238 }
Paul Mundtac44e662009-10-28 17:57:54 +0900239
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200240 if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
241 sh_perf_event_update(event, &event->hw, idx);
242 event->hw.state |= PERF_HES_UPTODATE;
243 }
244}
Paul Mundtac44e662009-10-28 17:57:54 +0900245
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200246static void sh_pmu_start(struct perf_event *event, int flags)
247{
248 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
249 struct hw_perf_event *hwc = &event->hw;
250 int idx = hwc->idx;
Paul Mundtac44e662009-10-28 17:57:54 +0900251
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200252 if (WARN_ON_ONCE(idx == -1))
253 return;
254
255 if (flags & PERF_EF_RELOAD)
256 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
257
258 cpuc->events[idx] = event;
259 event->hw.state = 0;
260 sh_pmu->enable(hwc, idx);
261}
262
263static void sh_pmu_del(struct perf_event *event, int flags)
264{
265 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
266
267 sh_pmu_stop(event, PERF_EF_UPDATE);
268 __clear_bit(event->hw.idx, cpuc->used_mask);
Paul Mundtac44e662009-10-28 17:57:54 +0900269
270 perf_event_update_userpage(event);
271}
272
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200273static int sh_pmu_add(struct perf_event *event, int flags)
Paul Mundtac44e662009-10-28 17:57:54 +0900274{
275 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
276 struct hw_perf_event *hwc = &event->hw;
277 int idx = hwc->idx;
Peter Zijlstra24cd7f52010-06-11 17:32:03 +0200278 int ret = -EAGAIN;
Paul Mundtac44e662009-10-28 17:57:54 +0900279
Peter Zijlstra33696fc2010-06-14 08:49:00 +0200280 perf_pmu_disable(event->pmu);
Paul Mundtac44e662009-10-28 17:57:54 +0900281
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200282 if (__test_and_set_bit(idx, cpuc->used_mask)) {
Paul Mundtac44e662009-10-28 17:57:54 +0900283 idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
284 if (idx == sh_pmu->num_events)
Peter Zijlstra24cd7f52010-06-11 17:32:03 +0200285 goto out;
Paul Mundtac44e662009-10-28 17:57:54 +0900286
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200287 __set_bit(idx, cpuc->used_mask);
Paul Mundtac44e662009-10-28 17:57:54 +0900288 hwc->idx = idx;
289 }
290
291 sh_pmu->disable(hwc, idx);
292
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200293 event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
294 if (flags & PERF_EF_START)
295 sh_pmu_start(event, PERF_EF_RELOAD);
Paul Mundtac44e662009-10-28 17:57:54 +0900296
297 perf_event_update_userpage(event);
Peter Zijlstra24cd7f52010-06-11 17:32:03 +0200298 ret = 0;
299out:
Peter Zijlstra33696fc2010-06-14 08:49:00 +0200300 perf_pmu_enable(event->pmu);
Peter Zijlstra24cd7f52010-06-11 17:32:03 +0200301 return ret;
Paul Mundtac44e662009-10-28 17:57:54 +0900302}
303
304static void sh_pmu_read(struct perf_event *event)
305{
306 sh_perf_event_update(event, &event->hw, event->hw.idx);
307}
308
Peter Zijlstrab0a873e2010-06-11 13:35:08 +0200309static int sh_pmu_event_init(struct perf_event *event)
Paul Mundtac44e662009-10-28 17:57:54 +0900310{
Peter Zijlstrab0a873e2010-06-11 13:35:08 +0200311 int err;
312
Stephane Eranian2481c5f2012-02-09 23:20:59 +0100313 /* does not support taken branch sampling */
314 if (has_branch_stack(event))
315 return -EOPNOTSUPP;
316
Peter Zijlstrab0a873e2010-06-11 13:35:08 +0200317 switch (event->attr.type) {
318 case PERF_TYPE_RAW:
319 case PERF_TYPE_HW_CACHE:
320 case PERF_TYPE_HARDWARE:
321 err = __hw_perf_event_init(event);
322 break;
323
324 default:
325 return -ENOENT;
326 }
327
Paul Mundtac44e662009-10-28 17:57:54 +0900328 if (unlikely(err)) {
329 if (event->destroy)
330 event->destroy(event);
Paul Mundtac44e662009-10-28 17:57:54 +0900331 }
332
Peter Zijlstrab0a873e2010-06-11 13:35:08 +0200333 return err;
Paul Mundtac44e662009-10-28 17:57:54 +0900334}
335
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200336static void sh_pmu_enable(struct pmu *pmu)
Peter Zijlstra33696fc2010-06-14 08:49:00 +0200337{
338 if (!sh_pmu_initialized())
339 return;
340
341 sh_pmu->enable_all();
342}
343
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200344static void sh_pmu_disable(struct pmu *pmu)
Peter Zijlstra33696fc2010-06-14 08:49:00 +0200345{
346 if (!sh_pmu_initialized())
347 return;
348
349 sh_pmu->disable_all();
350}
351
Peter Zijlstra51b0fe32010-06-11 13:35:57 +0200352static struct pmu pmu = {
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200353 .pmu_enable = sh_pmu_enable,
354 .pmu_disable = sh_pmu_disable,
Peter Zijlstrab0a873e2010-06-11 13:35:08 +0200355 .event_init = sh_pmu_event_init,
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200356 .add = sh_pmu_add,
357 .del = sh_pmu_del,
358 .start = sh_pmu_start,
359 .stop = sh_pmu_stop,
Paul Mundtac44e662009-10-28 17:57:54 +0900360 .read = sh_pmu_read,
361};
362
Peter Zijlstra3f6da392010-03-05 13:01:18 +0100363static void sh_pmu_setup(int cpu)
Paul Mundtac44e662009-10-28 17:57:54 +0900364{
365 struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
366
367 memset(cpuhw, 0, sizeof(struct cpu_hw_events));
368}
369
Peter Zijlstra3f6da392010-03-05 13:01:18 +0100370static int __cpuinit
371sh_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
372{
373 unsigned int cpu = (long)hcpu;
374
375 switch (action & ~CPU_TASKS_FROZEN) {
376 case CPU_UP_PREPARE:
377 sh_pmu_setup(cpu);
378 break;
379
380 default:
381 break;
382 }
383
384 return NOTIFY_OK;
385}
386
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200387int __cpuinit register_sh_pmu(struct sh_pmu *_pmu)
Paul Mundtac44e662009-10-28 17:57:54 +0900388{
389 if (sh_pmu)
390 return -EBUSY;
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200391 sh_pmu = _pmu;
Paul Mundtac44e662009-10-28 17:57:54 +0900392
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200393 pr_info("Performance Events: %s support registered\n", _pmu->name);
Paul Mundtac44e662009-10-28 17:57:54 +0900394
Peter Zijlstraa4eaf7f2010-06-16 14:37:10 +0200395 WARN_ON(_pmu->num_events > MAX_HWEVENTS);
Paul Mundtac44e662009-10-28 17:57:54 +0900396
Peter Zijlstra2e80a822010-11-17 23:17:36 +0100397 perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
Peter Zijlstra3f6da392010-03-05 13:01:18 +0100398 perf_cpu_notifier(sh_pmu_notifier);
Paul Mundtac44e662009-10-28 17:57:54 +0900399 return 0;
400}